Methods for degating molded parts from a runner

ABSTRACT

A system for removing from a molding tool a runner assembly having a plurality of molded parts that are connected to a runner via gates and subsequently degating the plurality of molded parts from the runner is provided. The system includes a source of ultrasonic energy and a robot arm assembly. The robot arm assembly is configured to remove the runner assembly from the molding tool and to position the runner assembly proximate the source of ultrasonic energy.

FIELD OF THE INVENTION

[0001] The present invention generally relates to the degating of moldedparts from a runner and more particularly to a system and method forremoving from a molding tool a plurality of molded parts that areconnected to a runner via gates and subsequently degating the pluralityof molded parts from said runner in a single phase operation.

BACKGROUND OF THE INVENTION

[0002] The injection molding of thermoplastic molded parts typicallyinvolves the injection of molten thermoplastic material into a mold thatprovides for the connection of a plurality of molded parts to a runner,referred to herein as a “runner assembly.” By molding the runnerassembly so that the molded parts are connected to a runner, the moldedparts may be removed from the mold at one time by simply removing therunner assembly. This eliminates the need to remove the molded partsindividually, and thus increases throughput. Typically, each of themolded parts is connected to the runner via a gate, which is a thin ornarrow portion of the thermoplastic material. After the runner assemblyis removed from the molding tool, the molded parts may be separated fromthe runner by cutting, breaking or melting the gate.

[0003] The separation of molded parts from runners through theintroduction of ultrasonic energy into the gate is referred to asultrasonic degating. Sources of ultrasonic energy include ultrasonichorns which, when positioned suitably close to the runners,ultrasonically excite the gates by producing mechanical vibrations inthe runner. The mechanical vibrations generate a standing wave of energydown the runner through the gate and into the molded part, whichresonates. The freely resonating part goes through a cyclic bendingmoment with the gate which induces stress into the gate and generatesinternal molecular friction. The internal molecular friction raises thetemperature of the gates. When the melting temperature of the gate isreached, the molded part is separated from the runner.

[0004] The removal of the runner assembly from the molding tool and thedegating of the molded parts from the runner are typically performedduring a multiple phase operation. First, the runner is removed from themolded tool manually by a first automatic holder and stored in acollection unit. The runner assembly may then be removed from thecollection unit and manually or mechanically positioned in a secondholder proximate to an ultrasonic horn for degating. Alternatively, therunner assembly may be manually or mechanically placed on a conveyorbelt after removal from the molding tool and transferred from the moldedtool to the ultrasonic horn. The runner assembly may then be manually ormechanically positioned in a second holder for degating. However, thismultiple phase operation limits throughput of the injection moldingprocess. In addition, because of the handling of the runner assembly bymultiple holders, the multiple phase operation risks breaking of therunner assembly. Further, multiple phase operations are typicallyexpensive due to the additional hardware and tooling required tofacilitate the multiple phases of operation.

[0005] Accordingly, there is a need for a system and method for removingfrom a molding tool a runner assembly and subsequently degating themolded parts from the runner of the runner assembly in a singleoperation.

SUMMARY OF THE INVENTION

[0006] This summary of the invention section is intended to introducethe reader to aspects of the invention and is not a complete descriptionof the invention. Particular aspects of the invention are pointed out inother sections hereinbelow, and the invention is set forth in theappended claims which alone demarcate its scope.

[0007] In accordance with an exemplary embodiment of the presentinvention, a system for removing from a molding tool a runner assemblyhaving a plurality of molded parts that are connected to a runner viagates and subsequently degating the plurality of molded parts from therunner is provided. The system includes a source of ultrasonic energyand a robot arm assembly. The robot arm assembly is configured to removethe runner assembly from the molding tool and to position the runnerassembly proximate the source of ultrasonic energy.

[0008] In accordance with another exemplary embodiment of the presentinvention, a method for degating a plurality of molded parts that areconnected to a runner via gates is provided. The method includes causinga robot arm assembly to position the plurality of molded parts and therunner proximate to a source of ultrasonic energy. The method alsoincludes pressing the runner against the source of ultrasonic energy.The method further includes activating the source of ultrasonic energyso that the plurality of molded parts is degated from the runner.

[0009] In accordance with a further exemplary embodiment of the presentinvention, a robot arm assembly for holding a runner assembly comprisinga plurality of molded parts and a runner connected thereto duringdegating of the plurality of molded parts from the runner is provided.The robot arm assembly includes a robot arm configured to transport therunner assembly from a molding tool to a source of ultrasonic energy.The robot arm assembly also includes a carrier assembly configured tohold the runner assembly.

[0010] These and other aspects of the present invention are described inthe following description, attached drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A more complete understanding of the present invention may bederived by referring to the detailed description and claims, consideredin connection with the figures, wherein like reference numbers refer tosimilar elements throughout the figures, and:

[0012]FIG. 1a is a schematic illustration of a top view of a typicalrunner assembly;

[0013]FIG. 1b is a schematic illustration of a side view of the runnerassembly of FIG. 1a;

[0014]FIG. 2a is a schematic illustration of a top view of anothertypical runner assembly;

[0015]FIG. 2b is a schematic illustration of a side view of the runnerassembly of FIG. 2a;

[0016]FIG. 3 is a schematic illustration of an exemplary embodiment ofthe system of the present invention;

[0017]FIG. 4a is a schematic illustration of a bottom view of a carrierassembly in accordance with an exemplary embodiment of the presentinvention;

[0018]FIG. 4b is a schematic illustration of a side view of the carrierassembly of FIG. 4a;

[0019]FIG. 5a is a schematic illustration of a bottom view of a carrierassembly in accordance with another exemplary embodiment of the presentinvention;

[0020]FIG. 5b is a schematic illustration of a side view of the carrierassembly of FIG. 5a;

[0021]FIG. 6 is a schematic illustration of a carrier assembly and anultrasonic degating assembly in accordance with an exemplary embodimentof the present invention;

[0022]FIG. 7 is a schematic illustration of the carrier assembly of FIG.6 pressing a runner assembly against the ultrasonic degating assembly ofFIG. 6;

[0023]FIG. 8a is a schematic illustration of a side view of a piston inaccordance with an exemplary embodiment of the present invention;

[0024]FIG. 8b is a schematic illustration of a bottom view of the pistonof FIG. 8a;

[0025]FIG. 9 is a schematic illustration of a top view of a base of anultrasonic degating assembly in accordance with an exemplary embodimentof the present invention;

[0026]FIG. 10 is a top view of an ultrasonic horn in accordance with anexemplary embodiment of the present invention; and

[0027]FIG. 11 is a top view of an ultrasonic horn, in accordance with anexemplary embodiment of the present invention, with a runner assemblysuperimposed thereon.

[0028] Skilled artisans will appreciate that elements in the figures areillustrated for simplicity and clarity and have not necessarily beendrawn to scale. For example, the dimensions of some of the elements inthe figures may be exaggerated relative to other elements to help toimprove understanding of embodiments of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0029] The following description is of exemplary embodiments only and isnot intended to limit the scope, applicability or configuration of theinvention in any way. Rather, the following description provides aconvenient illustration for implementing exemplary embodiments of theinvention. Various changes to the described embodiments may be made inthe function and arrangement of the elements described without departingfrom the scope of the invention as set forth in the appended claims.

[0030]FIGS. 1a and 1 b illustrate one example of a typical runnerassembly 10 formed after injection molding of a thermoplastic materialinto an injection mold. Runner assembly 10 comprises a plurality ofmolded parts 20 a, 20 b, 20 c, 20 d, 20 e, 20 f; 20 g and 20 h, whichare connected to at least one runner 40 via a plurality of gates 30 a,30 b, 30 c, 30 d, 30 e, 30 f, 30 g, and 30 h, respectively. Runner 40includes a main runner 44 which is integrally connected to cross runners46, which in turn are integrally connected to gates 30 a-30 h. Runner 40includes a sprue 42 that extends from the runner and is configured topermit a sprue gripper to grip and hold runner assembly 10. Runnerassembly 10 may also have an under-sprue 42 a that is formed duringmolding of the runner assembly. The thickness T₁ of main runner 44 froma center plane 48 to a bottom surface of main runner 44 may be greaterthan a thickness T₂ of cross runner 46 from center plane 48. The runnerassembly 10 may be formed of polystyrene, acrylonitrile butadienestyrene, polycarbonate, acrylic, nylon, glass filament material, andother suitable thermoplastic materials. While FIGS. 1a and 1 billustrate eight molded parts attached to a runner, it will beappreciated that any suitable number of molded parts may be connected tothe runner. In addition, molded parts 20 may be of any suitable size orshape.

[0031]FIGS. 2a and 2 b illustrate another example of a typical runnerassembly 60 formed after injection molding. Runner assembly 60 comprisesa plurality of molded parts 90 a and 90 b that are connected to a runner70 via gates 80 a and 80 b, respectively. Runner 70 includes a sprue 72that extends from runner 70 and is configured to permit a sprue gripperto grip and hold runner assembly 60. Runner assembly 60 may also have anunder-sprue 72 a that is formed during molding of the runner assembly.It will be appreciated that runner assemblies suitable for use in thepresent invention are not limited to the two above-described examplesbut may be configured in any design suitable for injection molding ofmolded parts.

[0032]FIG. 3 illustrates an exemplary embodiment of the system of thepresent invention. The system includes a robot arm assembly 100. Robotarm assembly 100 is suitably configured to remove a runner assembly 130from a molding tool 140 and transport runner assembly 130 to anultrasonic degating assembly 170. In one embodiment of the invention,robot arm assembly 100, molding tool 140 and ultrasonic degatingassembly 170 may be fixedly attached to a frame assembly (not shown) toprevent misalignment of the robot arm assembly 100 relative to themolding tool 140 and ultrasonic degating assembly 170. In an alternativeembodiment, one or more of the robot arm assembly 100, molding tool 140,and ultrasonic degating assembly 170 may be configured as a stand-aloneunit.

[0033] Robot arm assembly 100 includes an articulating robot arm 110 towhich is connected a carrier assembly 120. Robot arm assembly 100 isconfigured so that carrier assembly 120 may rotate and pivot relative torobot arm 110, as illustrated by arrows 150 and 160. Ultrasonic degatingassembly 170 includes a source of ultrasonic energy, such as anultrasonic horn 175. Ultrasonic horn 175 is preferably a bar horn,although any suitable ultrasonic horn may be used. Ultrasonic degatingassembly 170 also includes a base 180 to which ultrasonic horn 175 isinvertedly mounted. While only one ultrasonic horn 175 is illustrated inFIG. 3, it will be appreciated that, if a runner assembly issufficiently large in size or has multiple branches, two or moreultrasonic horns may be necessary for degating.

[0034]FIG. 10 illustrates one exemplary embodiment of a top surface ofan ultrasonic horn 175 of ultrasonic degating assembly 170 used fordegating a runner assembly, such as runner assembly 10 illustrated inFIG. 1a. Because many thermoplastic materials do not transmit ultrasonicenergy well enough to perform degating at points over 3 to 4 inches fromthe horn extremities, preferably horn 175 has a length “L” that is atleast equal to the length of the runner to be degated. For example, withrespect to runner assembly 10 of FIG. 1a, preferably horn 175 has alength “L” at least equal to, if not greater than, the length of mainrunner 44. Ultrasonic horn 175 may also include a groove 180 which isconfigured so that main runner 44 may be seated therein. Preferably,groove 180 has a sufficient depth to suitably receive main runner 44 sothat cross runners 46 contact surface areas 182 of the horn.Alternatively, if thickness T₁ of main runner 44 and thickness T₂ ofcross runner 46 are equal, groove 180 may not be necessary. Ultrasonichorn 175 may also have a clearance groove 184 that has a depth suitablefor receiving an under-sprue, such as under-sprue 42 a of runnerassembly 10. In an alternative embodiment, a hole may be formed inultrasonic horn 175 at a position suitable for receiving under-sprue 42a.

[0035]FIGS. 4a and 4 b illustrate a carrier assembly 120, according toone exemplary embodiment of the present invention, with a runnerassembly 130 illustrated in broken lines superimposed thereon. Carrierassembly 120 illustrated in FIGS. 4a and 4 b is configured to hold arunner assembly such as the runner assembly illustrated in FIGS. 1a and1 b. However, it will be appreciated that carrier assembly 120 may besuitably configured to hold assemblies of a variety of differentdesigns. Carrier assembly 120 includes a face plate 200 that is mountedto a frame 230. Frame 230 is movably mounted to robot arm 110. Aplurality of end effectors 210 a, 210 b, 210 c, 210 d, 210 e, 210 f, 210g, and 210 h are mounted to face plate 200. In a preferable embodimentof the invention, end effectors 210 are suction devices that are eachconnected to a vacuum source (not shown) via tubing 240 a, 240 b, 240 c,240 d, 240 e, 240 f, 240 g, and 240 h. While carrier assembly 120 isillustrated in FIGS. 4a and 4 b with eight end effectors, it will beappreciated that carrier assembly 120 may include any number of endeffectors suitable for holding a runner assembly. In a preferableembodiment of the invention, the number of end effectors corresponds tothe number of molded parts of the runner assembly. It will beappreciated, however, that any number of end effectors suitable forsecurely holding runner assembly(ies) may be used. End effectors 210a-210 h are suitably spaced so that, when holding runner assembly 130,each end effector holds a molded part that is to be degated from therunner of the runner assembly 130. A gripper assembly 250 is alsomounted to face plate 200 and is configured to grip the sprue of therunner assembly after the molded parts have been degated from therunner.

[0036] Carrier assembly 120 also includes piston assemblies 260 a and260 b, each having a piston 220 a and 220 b, respectively. Whenactivated, piston assemblies 260 a and 260 b cause pistons 220 a and 220b to move toward runner assembly 130 and press the runner of runnerassembly 130 against an ultrasonic horn (not shown). Preferably, pistons220 a and 220 b are of a suitable size and are positioned relative tothe runner at a suitable point proximate the gates so that as much ofthe ultrasonic energy from the ultrasonic horn as is practicable istransmitted along the runner to the gates while the amount of ultrasonicenergy transmitted to other points of the runner assembly other than thegates is minimized. FIGS. 8a and 8 b illustrate one embodiment of apiston 220. As shown, piston 220 may include a groove 610 configured sothat a portion of the runner of the runner assembly may be seatedtherein. With this configuration, piston 220 reduces or eliminatesmovement of the runner assembly relative to the ultrasonic horn of theultrasonic degating assembly during degating. Surface areas 620 a and620 b of piston 220 contact the runner assembly and press the runnerassembly against the ultrasonic horn. Preferably, contact areas 620 aand 620 b are of a sufficient size suitable for pressing the runnerassembly against the ultrasonic horn but are not so large so as todampen the ultrasonic energy transmitted along the runner to the gates.Referring to FIGS. 4a and 8 a, the width “W” of the total contact areaof piston 220 preferably is no greater than the width of the ultrasonichorn. To reduce the size of surface areas 620 a and 620 b, piston 220may also have beveled edges 600 a and 600 b. Beveled edges 600 a and 600b are suitably configured to reduce or eliminate damping of thetransmission of ultrasonic energy along the runner of the runnerassembly to the gates, thereby optimizing transmission. While piston 220is illustrated in FIGS. 8a and 8 b as having a circular cross-sectionalshape, it will be appreciated that piston 220 may be of a square,rectangular or other shape suitable for pressing the runner assemblyagainst the ultrasonic horn.

[0037]FIG. 5a and 5 b illustrate a carrier assembly 300, according toanother exemplary embodiment of the present invention, with two runnerassemblies 350 a and 350 b illustrated in broken lines superimposedthereon. Carrier assembly 300 illustrated in FIGS. 5a and 5 b isconfigured to hold at least one runner assembly such as the runnerassembly illustrated in FIGS. 2a and 2 b. However, it will beappreciated that carrier assembly 300 may be suitably configured to holdany number of runner assemblies of different designs. Carrier assembly300 includes a face place 310 mounted to a frame 320 which is movablyconnected to robot arm 110. A plurality of end effectors 330 a, 330 b,330 c, and 330 d are mounted to face plate 310. In a preferableembodiment of the invention, end effectors 330 are suction devices thatare connected to a vacuum source (not shown) via tubing 340 a, 340 b,340 c, and 340 d, respectively. While carrier assembly 300 isillustrated in FIGS. 5a and 5 b with two end effectors for each of therunner assemblies, it will be appreciated that carrier assembly 300 mayinclude any number of end effectors suitable for holding a runnerassembly. End effectors 330 a-330 d are suitably spaced so that, whenholding runner assemblies 350 a and 350 b, each end effector holds amolded part that is to be degated from the runner of the runnerassembly. Sprue gripper assemblies 360 a and 360 b are mounted to faceplate 310 and are configured to grip the sprue of the runner assemblies350 a and 350 b after the molded parts have been degated from therunner. In an alternative embodiment of the invention, runner assemblies350 a and 350 b may be held by sprue gripper assemblies 360 a and 360 bwithout using end effectors 330 a-330 d.

[0038] Carrier assembly 300 also includes piston assemblies 370 a and370 b, each having a piston 380 a and 380 b, respectively. Whenactivated, piston assemblies 370 a and 370 b cause pistons 380 a and 380b to move toward runner assemblies 350 a and 350 b and press runnerassemblies 350 a and 350 b against an ultrasonic horn (not shown).Preferably, pistons 380 a and 380 b are positioned on the runner at asuitable point so that transmission of the mechanical vibrations alongthe runner to the gates is optimized. As illustrated in FIGS. 5a and 5b, pistons 380 a and 380 b may be positioned proximate the midpoint ofthe runner so that the transmission of ultrasonic energy along therunner is maximized. In one embodiment of the invention, pistons 380 aand 380 b have recesses 382 a and 382 b for receiving sprues that may belocated at the runner assembly's midpoint. In an alternative embodimentof the invention, pistons 380 a and 380 b may have grooves formedtherein for recurring runner assemblies thereby reducing or eliminatingmovement of the runner assemblies relative to the ultrasonic horn.

[0039]FIG. 11 illustrates one exemplary embodiment for the positioningof an ultrasonic horn 390 relative to the runner assembly 350 (of FIGS.5a and 5 b) superimposed thereon. FIG. 11 also illustrates thepositioning of piston 380 relative to the runner assembly. Preferably,the contact area of piston 380 that contacts the runner assembly is ofsufficient size so as to suitably press the runner assembly againstultrasonic horn 390 but is not so large as to dampen the transmission ofultrasonic energy to the gates of the runner. Although not illustratedin FIG. 11, it will be appreciated that ultrasonic horn 390 may beconfigured to have grooves or recesses suitable to receive the runnerassembly and any under-sprue thereof. While one ultrasonic horn 390 isillustrated in FIG. 11 as proximate the midpoint of runner assembly 350,it should be understood that one or more ultrasonic horns may besuitably positioned proximate the runner so as to maximize transmissionof ultrasonic energy to the gates.

[0040] A method for degating molded parts from the runner of a runnerassembly using an exemplary embodiment of the system of the presentinvention will now be described. FIG. 6 illustrates a robot arm assembly400 holding a runner assembly 410 after runner assembly 410 has beenremoved from a molding tool (not shown). For purposes of this example,runner assembly 410 is of a design similar to that of runner assembly 10of FIGS. 1a and 1 b, although it will be appreciated that robot armassembly 400 may be configured to hold and process runner assemblies ofany suitable design. To remove runner assembly 410 from a molding tool(not show), robot arm 420 positions a carrier assembly 430 proximaterunner assembly 410 positioned in the molding tool. A plurality ofsuction devices 440 a-440 h are spaced so that when suitably positionedproximate the runner assembly 410, the suction devices are positionedproximate the molded parts of the runner assembly. Robot arm 420 thenadvances carrier assembly 430 towards runner assembly 410 so thatsuction devices 440 a-440 h contact the molded parts. Suction devices440 a-440 h are then activated so that a vacuum is created between themolded parts and suction devices 440 a-440 h. Robot arm 420 then movescarrier assembly 430 away from the molding tool thereby removing runnerassembly 410 therefrom.

[0041] Robot arm assembly 400 then positions runner assembly 410proximate an ultrasonic degating assembly 500, which includes a sourceof ultrasonic energy, such as ultrasonic horn 510. Ultrasonic horn 510is preferably a bar horn, although any suitable ultrasonic horn may beused. Ultrasonic degating assembly 500 also includes a base 520 to whichultrasonic horn 510 is invertedly mounted. Referring momentarily to FIG.9, in another embodiment of the invention, base 520 may include aplurality of openings 530 a-530 h. Openings 530 a-530 h are preferablypositioned below the molded parts of runner assembly 410 when runnerassembly 410 is suitably positioned proximate ultrasonic horn 510 sothat when the molded parts are degated from runner assembly 410, theyare free to drop through openings 530 a-530 h. While base 520 isillustrated in FIG. 9 having eight openings, it will be appreciated thatbase 520 may have any number of openings suitable for permitting themolded parts to drop from the runner for subsequent collection.

[0042] In another embodiment of the invention, ultrasonic degatingassembly 500 may also include a plurality of corresponding collectiontubes 540 a-540 h mounted to base 520, as illustrated in FIGS. 6 and 7,to direct the molded parts to collection buckets (not shown) or aconveyor belt (not shown) for use in subsequent manufacturing processes.While collection tubes 540 a-540 h are illustrated in FIGS. 6 and 7 asmounted to base 520 for direction of the molded parts for collection, itwill be appreciated that collection tubes 540 a-540 h are not essentialto the system of the present invention and the molded parts may be freeto drop from openings 530 a-530 h directly to collection buckets or aconveyor belt positioned proximate the ultrasonic degating assembly.

[0043] As illustrated in FIG. 7, robot arm assembly 400 advances runnerassembly 410 against the ultrasonic horn 510. Suction devices 440 a-440h are deactivated and piston assemblies 450 a and 450 b are activated tomove pistons 460 a and 460 b against the runner assembly 410 so that therunner of runner assembly 410 is pressed against ultrasonic horn 510.Pistons 460 a and 460 b press runner assembly 410 against ultrasonichorn 510 with sufficient force to cause ultrasonic vibrations to betransmitted from the horn to the runner and along the runner to thegates. Such force generally is in the range of about 10 lbs. to about 40lbs. but is preferably in the range of about 15 lbs to about 25 lbs. Theultrasonic horn typically is configured to emit ultrasonic energy at afrequency in the range of about 20 kHz to about 40 kHz. The ultrasonichorn is activated for a suitable amount of time to permit the moldedparts of runner assembly 410 to degate from the runner. Once the moldedparts have separated from the runner, a sprue gripper assembly 470 isthen activated to grasp a sprue of runner assembly 410 and remove thedegated runner from the ultrasonic degating assembly. Robot arm assembly400 then moves the degated runner from ultrasonic degating assembly 500so that the runner may be discarded.

[0044] In the foregoing specification, the invention has been describedwith reference to specific embodiments. However, one of ordinary skillin the art appreciates that various modifications and changes can bemade without departing from the scope of the present invention as setforth in the claims below. Accordingly, the specification and figuresare to be regarded in an illustrative rather than a restrictive sense,and all such modifications are intended to be included within the scopeof present invention.

[0045] Benefits, other advantages, and solutions to problems have beendescribed above with regard to specific embodiments. However, thebenefits, advantages, solutions to problems, and any element(s) that maycause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeatures or elements of any or all the claims. As used herein, the terms“comprises,” “comprising,” or any other variation thereof, are intendedto cover a non-exclusive inclusion, such that a process, method,article, or apparatus that comprises a list of elements does not includeonly those elements but may include other elements not expressly listedor inherent to such process, method, article, or apparatus.

What is claimed is:
 1. A system for removing from a molding tool arunner assembly comprising a plurality of molded parts that areconnected to a runner via gates and subsequently degating the pluralityof molded parts from the runner, said system comprising: a source ofultrasonic energy; and a robot arm assembly configured to remove therunner assembly from the molding tool and to position the runnerassembly proximate to the source of ultrasonic energy.
 2. The system ofclaim 1, said source of ultrasonic energy comprising an ultrasonic horn.3. The system of claim 1, said robot arm assembly comprising a robotarm.
 4. The system of claim 3, wherein said robot arm assembly comprisesa carrier assembly movably connected to said robot arm and configured tohold and carry the runner assembly.
 5. The system of claim 4, whereinsaid carrier assembly comprises at least one piston assembly configuredto press the runner against said source of ultrasonic energy.
 6. Thesystem of claim 5, wherein said at least one piston assembly comprises apiston having a groove configured to permit at least a portion of therunner to be positioned therein.
 7. The system of claim 4, wherein saidcarrier assembly comprises at least one end effector configured to holdat least a portion of said runner assembly.
 8. The system of claim 7,wherein said at least one end effector comprises a suction device. 9.The system of claim 4, wherein said carrier assembly comprises a gripperconfigured to grip a portion of the runner assembly.
 10. The system ofclaim 1, further comprising a base to which said source of ultrasonicenergy is invertedly mounted.
 11. The system of claim 10, wherein saidbase comprises at least one opening configured so that, when theplurality of molded parts is degated from the runner, at least one ofthe plurality of molded parts is permitted to drop through said at leastone opening for collection.
 12. The system of claim 11, furthercomprising at least one collection tube, wherein said at least onecollection tube is mounted to said base proximate to said at least oneopening to direct said molded parts from said at least one opening to acollection unit.
 13. The system of claim 12, said collection unitcomprising at least one collection bucket.
 14. The system of claim 12,said collection unit comprising a conveyor belt.
 15. The system of claim2, wherein said ultrasonic horn is configured to receive at least aportion of the runner assembly so that the transmission of ultrasonicenergy along the runner to the gates is optimized.
 16. A method fordegating a plurality of molded parts that are connected to a runner viagates, said method comprising: causing a robot arm assembly to positionthe plurality of molded parts and the runner proximate to a source ofultrasonic energy; pressing the runner against said source of ultrasonicenergy; and activating said source of ultrasonic energy so that theplurality of molded parts is degated from the runner.
 17. The method ofclaim 16, further comprising causing said robot arm assembly to discardthe runner.
 18. The method of claim 16, further comprising activatingthe robot arm assembly to remove the plurality of molded parts and therunner from a molding tool prior to said causing.
 19. The method ofclaim 16, wherein said pressing comprises causing said robot armassembly to press the runner against said source of ultrasonic energy.20. The method of claim 16, further comprising permitting the pluralityof molded parts to drop from the runner to a collector after theplurality of molded parts is degated from the runner.
 21. The method ofclaim 16, wherein said robot arm assembly comprises a carrier assemblyconfigured to hold and carry the plurality of molded parts and therunner.
 22. The method of claim 16, wherein said source of ultrasonicenergy is an ultrasonic horn.
 23. The method of claim 21, wherein saidcarrier assembly comprises at least one piston assembly configured topress the runner against said source of ultrasonic energy.
 24. Themethod of claim 23, wherein said at least one piston assembly comprisesa piston having a groove configured to permit at least a portion of therunner to be positioned therein.
 25. The method of claim 21, whereinsaid carrier assembly comprises at least one suction device.
 26. Themethod of claim 21, wherein said carrier assembly comprises a gripperconfigured to grip a portion of the runner.
 27. A robot arm assembly forholding a runner assembly comprising a plurality of molded parts and arunner connected thereto during degating of the plurality of moldedparts from the runner, the robot arm assembly comprising: a robot armconfigured to transport the runner assembly from a molding tool to asource of ultrasonic energy; and a carrier assembly configured to holdthe runner assembly.
 28. The robot arm assembly of claim 27, whereinsaid carrier assembly comprises: a face plate movably connected to saidrobot arm; at least one holding device connected to said face plate andconfigured to hold said runner assembly; and at least one pistonassembly connected to said face plate and configured to press saidrunner assembly against said source of ultrasonic energy.
 29. The robotarm assembly of claim 28, wherein said at least one holding devicecomprises a suction device.
 30. The robot arm assembly of claim 27,wherein said carrier assembly further comprises a gripper configured togrip a portion of the runner assembly.
 31. The robot arm assembly ofclaim 28, wherein said at least one piston assembly comprises a pistonconfigured to press the runner against said source of ultrasonic energy.32. The robot arm assembly of claim 31, wherein said piston comprises agroove configured to permit at least a portion of the runner to bepositioned therein.
 33. A method for removing from a molding tool aplurality of molded parts that are connected to a runner via gates andsubsequently degating the plurality of molded parts from the runner in asingle phase operation, said method comprising: activating a robot armassembly to remove the plurality of molded parts and the runner from themolding tool; causing said robot arm assembly to position the pluralityof molded parts and the runner proximate to a source of ultrasonicenergy; pressing the runner against said source of ultrasonic energy sothat when said source of ultrasonic energy is activated, a standing waveof mechanical vibration is transferred along the runner to the gates;activating said source of ultrasonic energy so that the plurality ofmolded parts is separated from the runner; and causing said robot armassembly to discard the runner.